Professions. One of many game content systems thats been criminally ignored, and needs a complete and total overhaul.
I mean wheres the creativity from blizzard, so much has changed with crafting in games since 2004 that even without creativity you can drastically improve this games side dish content, and all you need is to make a UI and a minigame that doesnt suckass. Keep in mind right now your crafting is press button watch bar mixed with crafting item bloat from 15 years of expansions.
Really anything can be done with professions, simply because nothing has been done, and its the same ancient crafting system since crafting was invented.
Just think of how many thousands of items exist in this game simply for this ancient crafting system. So much stuff in game that is irrelevant, it clutters your storage in game, probably causes spaghetti code issues having all that worthless code in there, ect.